Landscape drives zoonotic malaria prevalence in non-human primates.

Zoonotic disease dynamics in wildlife hosts are rarely quantified at macroecological scales due to the lack of systematic surveys. Non-human primates (NHPs) host Plasmodium knowlesi, a zoonotic malaria of public health concern and the main barrier to malaria elimination in Southeast Asia. Understanding of regional P. knowlesi infection dynamics in wildlife is limited. Here, we systematically assemble reports of NHP P. knowlesi and investigate geographic determinants of prevalence in reservoir species. Meta-analysis of 6322 NHPs from 148 sites reveals that prevalence is heterogeneous across Southeast Asia, with low overall prevalence and high estimates for Malaysian Borneo. We find that regions exhibiting higher prevalence in NHPs overlap with human infection hotspots. In wildlife and humans, parasite transmission is linked to land conversion and fragmentation. By assembling remote sensing data and fitting statistical models to prevalence at multiple spatial scales, we identify novel relationships between P. knowlesi in NHPs and forest fragmentation. This suggests that higher prevalence may be contingent on habitat complexity, which would begin to explain observed geographic variation in parasite burden. These findings address critical gaps in understanding regional P. knowlesi epidemiology and indicate that prevalence in simian reservoirs may be a key spatial driver of human spillover risk.

Zoonotic diseases are infectious diseases that are transmitted from animals to humans. For example, the malaria-causing parasite Plasmodium knowlesi can be transmitted from monkeys to humans through mosquitos that have previously fed on infected monkeys. In Malaysia, progress towards eliminating malaria is being undermined by the rise of human incidences of 'monkey malaria', which has been declared a public health threat by The World Health Organisation. In humans, cases of monkey malaria are higher in areas of recent deforestation. Changes in habitat may affect how monkeys, insects and humans interact, making it easier for diseases like malaria to pass between them. Deforestation could also change the behaviour of wildlife, which could lead to an increase in infection rates. For example, reduced living space increases contact between monkeys, or it may prevent behaviours that help animals to avoid parasites. Johnson et al. wanted to investigate how the prevalence of malaria in monkeys varies across Southeast Asia to see whether an increase of Plasmodium knowlesi in primates is linked to changes in the landscape. They merged the results of 23 existing studies, including data from 148 sites and 6322 monkeys to see how environmental factors like deforestation influenced the amount of disease in different places. Many previous studies have assumed that disease prevalence is high across all macaques, monkey species that are considered pests, and in all places. But Johnson et al. found that disease rates vary widely across different regions. Overall disease rates in monkeys are lower than expected (only 12%), but in regions with less forest or more 'fragmented' forest areas, malaria rates are higher. Areas with a high disease rate in monkeys tend to further coincide with infection hotspots for humans. This suggests that deforestation may be driving malaria infection in monkeys, which could be part of the reason for increased human infection rates. Johnsons et al.'s study has provided an important step towards better understanding the link between deforestation and the levels of monkey malaria in humans living nearby. Their study provides important insights into how we might find ways of managing the landscape better to reduce health risks from wildlife infection.

Engineered CBEs based on Macaca fascicularis A3A with improved properties for precise genome editing.

Cytidine deaminase defines the properties of cytosine base editors (CBEs) for C-to-T conversion. Replacing the cytidine deaminase rat APOBEC1 (rA1) in CBEs with a human APOBEC3A (hA3A) improves CBE properties. However, the potential CBE application of macaque A3A orthologs remains undetermined. Our current study develops and evaluates engineered CBEs based on Macaca fascicularis A3A (mA3A). Here, we demonstrate that BE4-mA3A and its RNA-editing-derived variants exhibit improved CBE properties, except for DNA off-target activity, compared to BE3-rA1 and BE4-rA1. Unexpectedly, deleting Ser-Val-Arg (SVR) in BE4-mA3A dramatically reduces DNA and RNA off-target activities and improves editing accuracy, with on-target efficiency unaffected. In contrast, a chimeric BE4-hA3A-SVR+ shows editing efficiency increased by about 50%, with other properties unaffected. Our findings demonstrate that mA3A-based CBEs could provide prototype options with advantages over rA1- and hA3A-based CBEs for further optimization, highlighting the importance of the SVR motif in defining CBE intrinsic properties.

Dl-3-n-Butylphthalide Alleviates Secondary Brain Damage and Improves Working Memory After Stroke in Cynomolgus Monkeys.

BACKGROUND: Remote secondary neurodegeneration is associated with poststroke cognitive impairment (PSCI). Dl-3-n-butylphthalide (NBP) improves PSCI clinically. However, whether it ameliorates PSCI by alleviating secondary neurodegeneration remains uncertain. Nonhuman primates provide more relevant models than rodents for human stroke and PSCI. This study investigated the effects of NBP on PSCI and secondary neurodegeneration in cynomolgus monkeys after permanent left middle cerebral artery occlusion (MCAO). METHODS: Thirteen adult male cynomolgus monkeys were randomly assigned to sham (n=4), MCAO+placebo (n=5), and MCAO+NBP groups (n=4). The MCAO+placebo and MCAO+NBP groups received saline and NBP injections intravenously, respectively, starting at 6-hour postsurgery for 2 weeks, followed by soybean oil and NBP orally, respectively, for 10 weeks after MCAO. Infarct size was assessed at week 4 by magnetic resonance imaging. Working memory and executive function were evaluated dynamically using the delayed response task and object retrieval detour task, respectively. Neuron loss, glia proliferation, and neuroinflammation in the ipsilateral dorsal lateral prefrontal cortex, thalamus, and hippocampus were analyzed by immunostaining 12 weeks after MCAO. RESULTS: Infarcts were located in the left middle cerebral artery region, apart from the ipsilateral dorsal lateral prefrontal cortex, thalamus, or hippocampus, with no significant difference between the MCAO+placebo and MCAO+NBP group. Higher success in delayed response task was achieved at weeks 4, 8, and 12 after NBP compared with placebo treatments (P<0.05), but not in the object retrieval detour task (all P>0.05). More neurons and less microglia, astrocytes, CD68-positive microglia, tumor necrosis factor-α, and inducible NO synthase were observed in the ipsilateral dorsal lateral prefrontal cortex and thalamus after 12 weeks of NBP treatment (P<0.05), but not in the hippocampus (P>0.05). CONCLUSIONS: Our findings indicate that NBP improves working memory by alleviating remote secondary neurodegeneration and neuroinflammation in the ipsilateral dorsal lateral prefrontal cortex and thalamus after MCAO in cynomolgus monkeys.

Cerebral asymmetry in adult Macaca fascicularis as revealed by voxel-based MRI and DTI analysis.

Investigating cerebral asymmetries in non-human primates would facilitate to understand the evolutional traits of the human brain specialization related to language and other high-level cognition. However, brain asymmetrical studies of monkeys produced controversial results. Here, we investigated the cerebral asymmetries using a combination of the optimized voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) protocols in monkeys. The study-specific MRI and DTI-based templates were created in 66 adult Macaca fascicularis, and the asymmetrical index of grey and white matter was subsequently examined. The VBM analysis detected the well-known frontal and occipital petalias and confirmed the presence of leftward asymmetry in the ventral frontal cortex. A marked leftward asymmetry of anterior superior temporal gyrus but not posterior portion were found. We also identified grey matter asymmetries in some regions that were not previously reported including rightward anterior cingulate, insular cortex and thalamus, and leftward caudate. In contrast, the results of TBSS analysis for the first time revealed the robust leftwards asymmetries of corpus callosum (splenium and body), internal/external capsule, and white matter in middle temporal gyrus, adjacent thalamus and amygdala whereas the rightwards in uncinate fasciculus, posterior thalamic radiation and cerebral peduncle. These findings provide robust evidence of grey and white matter asymmetries in the brain of monkeys, which may extend the understanding of brain evolution in cerebral specialization.

Influence of COVID-19 on the emergence of stone-tool use behavior in a population of common long-tailed macaques (Macaca fascicularis fascicularis) in Thailand.

Stone tool use is a rare behavior across nonhuman primates. Here we report the first population of common long-tailed macaques (Macaca fascicularis fascicularis) who customarily used stone tools to open rock oysters (Saccostrea forskali) on a small island along the Thai Gulf in Koh Ped (KPE), eastern Thailand. We observed this population several times during the past 10 years, but no stone-tool use behavior was observed until our survey during the coronavirus disease 2019 (COVID-19) pandemic in July 2022. KPE is located in Pattaya City, a hotspot for tourism in Thailand. Tourists in this area frequently provided large amounts of food for the monkeys on KPE. During the COVID-19 curfew, however, tourists were not allowed to access the island, and monkeys began to face food scarcity. During this time, we observed stone-tool use behavior for the first time on KPE. Based on our observations, the first tool manipulation was similar to stone throwing (a known precursor of stone tool use). From our observations in March 2023, we found 17 subadult/adult animals performing the behavior, 15 of 17 were males and mostly solitary while performing the behavior. The M. f. fascicularis subspecies was confirmed by distribution, morphological characteristics, and mtDNA and SRY gene sequences. Taken together, we proposed that the stone tool use behavior in the KPE common long-tailed macaques emerged due to the COVID-19 food scarcity. Since traveling is no longer restricted many tourists have started coming back to the island, and there is a high risk for this stone tool-use behavior to disappear within this population of long-tailed macaques.

Evidence of potential Campylobacter jejuni zooanthroponosis in captive macaque populations.

Non-human primates share recent common ancestry with humans and exhibit comparable disease symptoms. Here, we explored the transmission potential of enteric bacterial pathogens in monkeys exhibiting symptoms of recurrent diarrhoea in a biomedical research facility in China. The common zoonotic bacterium Campylobacter jejuni was isolated from macaques (Macaca mulatta and Macaca fascicularis) and compared to isolates from humans and agricultural animals in Asia. Among the monkeys sampled, 5 % (44/973) tested positive for C. jejuni, 11 % (5/44) of which displayed diarrhoeal symptoms. Genomic analysis of monkey isolates, and 1254 genomes from various sources in Asia, were used to identify the most likely source of human infection. Monkey and human isolates shared high average nucleotide identity, common MLST clonal complexes and clustered together on a phylogeny. Furthermore, the profiles of putative antimicrobial resistance genes were similar between monkeys and humans. Taken together these findings suggest that housed macaques became infected with C. jejuni either directly from humans or via a common contamination source.

Impact of administering umbilical cord-derived mesenchymal stem cells to cynomolgus monkeys with endometriosis.

Purpose: This study aimed to explore whether umbilical cord-derived mesenchymal stem cells (UC-MSCs) could be used as a therapeutic resource for endometriosis. Methods: Of seven cynomolgus monkeys with endometriosis, five were administered UC-MSCs (intervention group) and two were administered saline (control group). First, intravenous US-MSC treatment was administered for three months. Second, weekly intravenous US-MSC administration combined with monthly intraperitoneal US-MSC administration was conducted for 3 months. Finally, weekly intraperitoneal US-MSC administration was conducted for 3 months. The dose of UC-MSCs was set to 2 × 106 cells/kg for all administration routes. Laparoscopic findings and serum cancer antigen 125 (CA125) levels were also evaluated. The Revised American Society for Reproductive Medicine classification was used for laparoscopic evaluation. Results: Laparoscopic findings showed exacerbation of endometriosis after intraperitoneal UC-MSC administration, although no changes were observed in the control group. Intravenous UC-MSC administration decreased the level of CA125 in all monkeys; however, the difference was not significant. Intraperitoneal UC-MSC administration significantly exacerbated endometriosis compared with intravenous administration (p = 0.02). Conclusions: This study revealed that intraperitoneal UC-MSC administration exacerbates endometriosis in a nonhuman primate model of the disease.

Klebsiella pneumoniae infection in cynomolgus monkeys at primate research center facility in Indonesia.

BACKGROUND: Klebsiella pneumoniae infection in nonhuman primates has been widely reported and causes significant morbidity and mortality. Animal deaths occur routinely at the Primate Research Center of IPB University. The results of necropsy and culture suggested a K. pneumoniae infection. METHODS: A mass health assessment of Cynomolgus monkeys (n = 429) was carried out by physical examination and molecular targeting K. pneumoniae (n = 96), family of Coronaviridae (n = 148) and Paramyxoviridae (n = 148). RESULTS: A total of 49.18% of the animals had clinical symptoms of respiratory disorders, abscesses, trauma, and others. PCR results indicated that 28.57% were positive for K. pneumoniae with 35.71% mortality, while all samples were negative for both virus families. CONCLUSIONS: There have been outbreaks caused by K. pneumoniae and/or K. pneumoniae subsp. pneumoniae. This disease is chronic, infects all of the buildings, and no tendency for disease transmission according to gender and age class.

Inactivated SARS-CoV-2 vaccine candidate immunization on non-human primate animal model: B-cell and T-cell responses immune evaluation.

Background: SARS-CoV-2 vaccine was proven to be an effective and efficient measure for mitigating pandemic. COVID-19 infection and mortality subsided along with the increaseing COVID-19 vaccination coverage. Vaccine and health resource equity are predominant factors in COVID-19 pandemic management. Vaccine development for Indonesia, aims to ensure a sustainable pandemic control and steady national stability restoration. A decent vaccine must induce immunity against COVID-19 with minimum adverse reaction. Immunogenicity and ability to induce neutralizing antibody evaluation needs to be performed as part of the SARS-CoV-2 inactivated vaccine development from East Java, Indonesia isolate (Vaksin Merah Putih-INAVAC). Objective: This research demonstrated INAVAC performance in inducing the production neutralizing antibody along with its effects on CD4+ and CD8+ cells response in Macaca fascicularis (non-human primate). Methods: Two dosages of 3 µg and 5 µg were tested, compared to sham (NaCl 0.9%) in 10 Macaca fascicularis (2 injection intramuscular with 14 days interval). All animals were monitored daily for clinical signs. Nasopharyngeal samples were analyzed using qRT-PCR while the serum were tested using ELISA and neutralization assay, whereas PBMCs were flowcytrometrically analyzed to measure CD4+ and CD8+ population. Results: It is observed that both vaccine doses could stimulate relatively similar immune response and neutralizing antibody (end GMT post challenge = 905,1), whereas higher CD8+ cells response were reported in the 5 µg group after the 3rd day post-challenge. The dose of vaccine that produce adequate immune cell stimulation with neutralizing antibody induction can be adopted to clinical study, as favorable result of these parameters could predict minimum adverse reaction from inflammation response with balanced immune response. Conclusions: Therefore, it is concluded that Vaksin Merah Putih-INAVAC with 3 µg dose showed a favorable potential to be developed and tested as human vaccine.

Similarities and differences in placental development between humans and cynomolgus monkeys.

Background: The placenta is an extraembryonic organ, which is essential to maintain a normal pregnancy. However, placental development in humans is poorly understood because of technical and ethical reasons. Methods: We analyzed the anatomical localization of each trophoblastic subtype in the cynomolgus monkey placenta by immunohistochemistry in the early second trimester. Histological differences among the mouse, cynomolgus monkey, and human placenta were compared. The PubMed database was used to search for studies on placentation in rodents and primates. Main findings: The anatomical structures and subtypes of the placenta in cynomolgus monkeys are highly similar to those in humans, with the exception of fewer interstitial extravillous trophoblasts in cynomolgus monkeys. Conclusion: The cynomolgus monkey appears to be a good animal model to investigate human placentation.

Potential sex differences in activation of pain-related brain regions in nonhuman primates with a unilateral spinal nerve ligation.

The lack of truly robust analgesics for chronic pain is owed, in part, to the lack of an animal model that reflects the clinical pain state and of a mechanism-based, objective neurological indicator of pain. The present study examined stimulus-evoked brain activation with functional magnetic resonance imaging in male and female cynomolgus macaques following unilateral L7 spinal nerve ligation and the effects of clinical analgesics pregabalin, duloxetine, and morphine on brain activation in these macaques. A modified straight leg raise test was used to assess pain severity in awake animals and to evoke regional brain activation in anesthetized animals. The potential effects of clinical analgesics on both awake pain behavior and regional brain activation were examined. Following spinal nerve ligation, both male and female macaques showed significantly decreased ipsilateral straight leg raise thresholds, suggesting the presence of radicular-like pain. Morphine treatment increased straight leg raise thresholds in both males and females whereas duloxetine and pregabalin did not. In male macaques, the ipsilateral straight leg raise activated contralateral insular and somatosensory cortex (Ins/SII), and thalamus. In female macaques, the ipsilateral leg raise activated cingulate cortex and contralateral insular and somatosensory cortex. Straight leg raises of the contralateral, unligated leg did not evoke brain activation. Morphine reduced activation in all brain regions in both male and female macaques. In males, neither pregabalin nor duloxetine decreased brain activation compared with vehicle treatment. In females, however, pregabalin and duloxetine decreased the activation of cingulate cortex compared with vehicle treatment. The current findings suggest a differential activation of brain areas depending on sex following a peripheral nerve injury. Differential brain activation observed in this study could underlie qualitative sexual dimorphism in clinical chronic pain perception and responses to analgesics. Future pain management approaches for neuropathic pain will need to consider potential sex differences in pain mechanism and treatment efficacy.

Kidney cell culture Macaca fascicularis as a candidate for vaccine development and in vitro model.

BACKGROUND: Cell culture is the proliferation of a cell population in vitro by isolating from the original tissue or growing from existing ones. One essential source is the monkey kidney cell cultures which have an essential role in biomedical study. This is due to the significant homology between the human and macaque genomes making these useful for cultivating human viruses, especially enteroviruses, and growing vaccines. METHODS: This study developed cell cultures derived from the kidney of Macaca fascicularis (Mf) and validated its gene expression. RESULTS: The primary cultures were successfully subcultured up to six passages, grew as monolayers, and exhibited epithelial-like morphology. The cultured cells remained heterogeneous in phenotype and they expressed CD155 and CD46 as viral receptors, cell morphology (CD24, endosialin, and vWF), proliferation, also apoptosis markers (Ki67 and p53). CONCLUSIONS: These results indicated that the cell cultures can be used as in vitro model cells for vaccine development and bioactive compound.

Social disappointment and partner presence affect long-tailed macaque refusal behaviour in an 'inequity aversion' experiment.

Protest in response to unequal reward distribution is thought to have played a central role in the evolution of human cooperation. Some animals refuse food and become demotivated when rewarded more poorly than a conspecific, and this has been taken as evidence that non-human animals, like humans, protest in the face of inequity. An alternative explanation-social disappointment-shifts the cause of this discontent away from the unequal reward, to the human experimenter who could-but elects not to-treat the subject well. This study investigates whether social disappointment could explain frustration behaviour in long-tailed macaques, Macaca fascicularis. We tested 12 monkeys in a novel 'inequity aversion' paradigm. Subjects had to pull a lever and were rewarded with low-value food; in half of the trials, a partner worked alongside the subjects receiving high-value food. Rewards were distributed either by a human or a machine. In line with the social disappointment hypothesis, monkeys rewarded by the human refused food more often than monkeys rewarded by the machine. Our study extends previous findings in chimpanzees and suggests that social disappointment plus social facilitation or food competition effects drive food refusal patterns.

Whole-genome sequence of Macaca fascicularis: liver tissue.

OBJECTIVES: Thrombocytopenia is a condition that causes a low amount of blood platelets. Platelets are blood cells that play an essential role in blood coagulation. Therefore, thrombocytopenia can put the patient at risk for mild to severe bleeding. Thrombocytopenia is caused by a decrease in platelet production in the bone marrow or by a drug or immune system problem when production is normal. In particular, in some ASO-induced thrombocytopenia, the mechanism is not clear. Therefore, whole genome sequencing (WGS) was performed to discover genetic differences that affect thrombocytopenia and individual susceptibility to drugs between normal and reduced platelet monkeys despite administering the same ASO. DATA DESCRIPTION: Three antisense oligonucleotide (ASO) substances were injected into the subcutaneous tissue of monkeys for 12 weeks in two experiments. The monkeys were classified into three groups: monkeys with thrombocytopenia, monkeys without thrombocytopenia, and control monkeys not treated with ASO substances. Whole genome sequencing data was generated using liver tissues of monkeys. These data will be useful for identifying genetic differences that affect thrombocytopenia and drug sensitivity.

Age-Related Changes in the Clustering of Blood Populations in Cynomolgus Monkeys Depend on Sex and Immune Status.

Non-anthropoid primates cynomolgus monkeys (Macaca fascicularis), also known as crab-eating macaques, are increasingly used in biomedical and preclinical studies due to their evolutionary proximity to humans, sharing similar diets, infectious and senile diseases. Age-related changes and sexual dimorphism of the immune system of C. monkeys have not been sufficiently characterized in literature, though age and sex differences affect the course of diseases and sensitivity to medications. Aging in C. monkeys is accompanied by an increase in CD3+CD4+CD8+ (DP-T) cells, plasma B-cells, and a decrease in platelets. Erythromyeloid bias has also been noticed in older animals. There was an increase in eosinophils, haematocrit (HCT) and haemoglobin concentration (HGB). Senile decline in the function of the immune system had sex differences. An increase in the number of monocytes, cytotoxic lymphocytes (CTL) and a decrease in the T-helper population were more pronounced in older females. A significant reduction in the number of B-cells and activated T-cells was detected in males only. A moderate correlation with the regression model of aging was established for DP-T, HCT and HGB. The reduction in the B cells count in males and the increase in CTL level in females are moderately correlated with age. Other blood cell populations did not show significant correlations in the regression models due to their high sample variability. The novel cell population CD3-CD20loCD16/CD56+, presumably NK-cells subset, was revealed. This cell population demonstrated an increase trend with age in both sexes. Population-statistical age norms for different sexes for young and very old macaques were established. The blood population clusters associated with sex and immune status in older animals were also identified.

Healing Hanuman's Army: Veterinary Care as a Core Component of One Health Principles in a Southeast Asian Monkey Forest.

Wildlife that inhabit urban landscapes face the dual challenge of negotiating their positions in their group while navigating obstacles of anthropogenically modified landscapes. The dynamics of urban environments can result in novel injuries and mortalities for these animals. However, these negative impacts can be mitigated through planning, and onsite veterinary care like that provided by the Ubud Monkey Forest in Bali, Indonesia. We examined 275 recorded injuries and mortalities among six social groups of long-tailed macaques (Macaca fascicularis) brought to the veterinary clinic from 2015-2018. We fit the probabilities of injury vs. death among macaques brought to the clinic using a multilevel logistic regression model to infer the relationship between injury vs. death and associated demographic parameters. Males were more likely to sustain injuries and females were more likely to die. The frequency of injuries and mortalities changed over the four-year study period, which was reflected in our model. The odds of mortality were highest among young macaques and the odds of injury vs. mortality varied across the six social groups. We categorized injuries and mortalities as "natural" or "anthropogenic". Most injuries and mortalities were naturally occurring, but powerlines, motorized vehicles, and plastic present ongoing anthropogenic threats to macaque health. Most wounds and injuries were successfully treated, with healthy animals released back to their group. We suggest other sites with high levels of human-alloprimate interplays consider the Ubud Monkey Forest veterinary office as a model of care and potentially adopt their approaches.

Group-based, autonomous, individualized training and testing of long-tailed macaques (Macaca fascicularis) in their home enclosure to a visuo-acoustic discrimination task.

In recent years, the utility and efficiency of automated procedures for cognitive assessment in psychology and neuroscience have been demonstrated in non-human primates (NHP). This approach mimics conventional shaping principles of breaking down a final desired behavior into smaller components that can be trained in a staircase manner. When combined with home-cage-based approaches, this could lead to a reduction in human workload, enhancement in data quality, and improvement in animal welfare. However, to our knowledge, there are no reported attempts to develop automated training and testing protocols for long-tailed macaques (Macaca fascicularis), a ubiquitous NHP model in neuroscience and pharmaceutical research. In the current work, we present the results from 6 long-tailed macaques that were trained using an automated unsupervised training (AUT) protocol for introducing the animals to the basics of a two-alternative choice (2 AC) task where they had to discriminate a conspecific vocalization from a pure tone relying on images presented on a touchscreen to report their response. We found that animals (1) consistently engaged with the device across several months; (2) interacted in bouts of high engagement; (3) alternated peacefully to interact with the device; and (4) smoothly ascended from step to step in the visually guided section of the procedure, in line with previous results from other NHPs. However, we also found (5) that animals' performance remained at chance level as soon as the acoustically guided steps were reached; and (6) that the engagement level decreased significantly with decreasing performance during the transition from visual to acoustic-guided sections. We conclude that with an autonomous approach, it is possible to train long-tailed macaques in their social group using computer vision techniques and without dietary restriction to solve a visually guided discrimination task but not an acoustically guided task. We provide suggestions on what future attempts could take into consideration to instruct acoustically guided discrimination tasks successfully.

Fecal Microbiota Transplantation Could Improve Chronic Diarrhea in Cynomolgus Monkey by Alleviating Inflammation and Modulating Gut Microbiota.

Chronic diarrhea is associated with enteric dysbiosis and provokes the overuse of antibiotics. Fecal microbiota transplantation (FMT) is a promising therapy, but it shows discrepant clinical efficacy. Bacterial colonization in recipients has been studied, although little is known about the role of gut fungi and Archaea after FMT. In this study, we evaluated the efficacy of human-derived FMT on spontaneous chronic diarrhea cynomolgus monkeys and revealed the effector mechanisms. We demonstrated that FMT can mitigate the appearance of diarrheal symptoms and inhibit the increase in interleukin-6, interleukin-8, interleukin-1ß, and interferon-γ and the decrease in interleukin-10 in serum. We confirmed that FMT restored the disturbance of gut bacteria by reducing the relative abundances of potential pathogens, including Cloacibacillus porcorum, Desulfovibrio desulfuricans, Erysipelotrichaceae bacterium 5_2_54FAA, and Erysipelotrichaceae bacterium 21_3, and increasing the levels of Lactobacillus fermentum and Lactobacillus ruminis CAG_367 in diarrheal monkeys. The metabolic pathways of healthy and FMT monkeys' gut bacteria were enriched in amino acid metabolism, carbohydrate metabolism, and lipid metabolism, while the metabolic pathways of pre-FMT monkeys' gut bacteria were enriched in antibiotic production. Moreover, a higher Ascomycota/Basidiomycota ratio, higher Aspergillus levels, and lower Trichosporon asahii abundance were present in intestinal fungi after FMT. Although the abundance of the Archaea Methanosphaera stastmanae did not change significantly, it was inversely correlated with the anti-inflammatory factor IL-4 after FMT. These results support the further development and application of FMT for chronic diarrhea.

Regional brain activation during rectal distention and attenuation with alosetron in a nonhuman primate model of irritable bowel syndrome.

Greater understanding of the mechanism that mediates visceral pain and hypersensitivity associated with irritable bowel syndrome (IBS) would facilitate the development of effective therapeutics to manage these symptoms. An objective marker associated with the underlying mechanisms of visceral pain and hypersensitivity could be used to guide therapeutic development. The current study examined brain activation evoked by rectal distention with functional magnetic resonance imaging (fMRI) in a cynomolgus macaque model of visceral hypersensitivity. Male, cynomolgus macaques underwent five four-week treatments of dextran sodium sulfate (DSS)-distilled water (DW), which induced mild-moderate colitis with remission during each treatment cycle. Balloon rectal distention (RD) was performed under anesthesia 14 weeks after the final DSS-DW treatment. Colonoscopy confirmed the absence of colitis prior to the start of RD. In naïve, untreated macaques, 10, 20 and 30 ml RD did not evoke brain activation. However, insular cortex/somatosensory II cortex and cerebellum were significantly activated in DSS-treated macaques at 20 and 30 ml rectal distention. Intra-rectal pressure after DSS treatment was not significantly different from that of naïve, untreated macaques, indicating lack of alteration of rectal functioning following DSS-treatment. Treatment with 5-HT3 receptor antagonist alosetron (p.o.) reduced distension-evoked brain activation and decreased intra-rectal pressure. The current findings demonstrated activation of brain regions to RD following DSS treatments which was not present in naïve macaques, suggesting visceral hypersensitivity. Brain activation in turn was reduced by alosetron, which could underlie the analgesic effect alosetron in IBS patients.

Mechanisms of expression of object play: A comparative study of stone handling in two captive groups of long-tailed macaques (Macaca fascicularis fascicularis).

Stone handling (SH) is a form of solitary object play that is socially learned and culturally maintained. We studied two captive groups (Modena, N = 20; Padova, N = 20) of common long-tailed macaques housed in a sanctuary in Italy. Our research goal was two-fold: (1) establish the first SH repertoire in captive-raised long-tailed macaques, and (2) explain major differences in the expression of SH between the two study groups. Despite being of identical size and sharing similar environmental conditions, we found that SH was performed by most group members in Modena, whereas SH was absent in Padova. We aimed to explain this inter-group variation by exploring the role of proximate factors that are known to affect the occurrence of SH: demography, dominance, stone availability, activity budget, and food provisioning. The atypical age structure of Padova (i.e., no immature individuals) may have impaired the emergence of SH in this group. In Modena, we found no significant effect of hierarchical rank on SH frequency and duration and no temporal relationship between SH and feeding. Regarding the activity budget, SH filled in for a portion of affiliative and resting behaviours in Modena. Our findings lend support to the cultural nature of SH.